Snapchat founder Evan Spiegel has said he is "devastated" and "angry" that plans for his messaging app were leaked as part of the Sony Pictures hack.
Details of future ideas and strategy were outlined by Mr Spiegel in emails to Michael Lynton, a Sony executive who sits on Snapchat's board.
Also included were details, including financial data, on previously unpublicised acquisitions.
"I felt like I was going to cry all morning," Mr Spiegel said in a memo.
"I went on a walk and thought through a couple things."
Mr Spiegel later shared on Twitter the emotional note he sent to Snapchat's employees, entitled Keeping Secrets.
"I've been feeling a lot of things since our business plans were made public last night," he wrote.
"Definitely angry. Definitely devastated.
"I want to give you all a huge hug because keeping secrets is exhausting.
"Keeping secrets means coming home late, after working all day and night. Curling up with your loved ones, hanging out with your friends, and not being able to share all of the incredible things you're working on. It's painful, it's tiring."
The leak detailed big ambitions for the popular app which allows users to send messages - images or video - that disappear after a short period of time.
According to the emails, the company purchased Vergence Labs, an eyewear company that produced a product comparable to Google Glass.
Snapchat also spent millions on Scan.me, a firm specialising in QR codes and advertising platform iBeacon.
Mr Spiegel's staff memo does not comment on the acquisitions, nor does it suggest the company planned to take any legal action against Sony or any other party.
Sony Pictures' legal woes are beginning to mount after the hack attack that has seen it cancel plans to release The Interview, a comedy about North Korea.
Earlier this week, two former Sony Pictures employees filed a lawsuit accusing the company of not properly securing private data.
Around 15,000 employees had personal information, including social security numbers, leaked following the hack.
Sony Pictures said the attack was "unprecedented", and that the threat was "undetectable by industry-standard antivirus software".
Mr Spiegel has said he will spend some time being "angry and upset" before getting back to work.
"It's not fair that the people who try to build us up and break us down get a glimpse of who we really are.
"It's not fair that people get to take away all the hard work we've done to surprise our community, family and friends."
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